Diagnostic Ability of Impulse Oscillometry in Diagnosis of Chronic Obstructive Pulmonary Disease

Abstract

The diagnosis of chronic obstructive pulmonary disease (COPD) mainly relies on spirometry. Due to the complexity of spirometry, easier-to-do impulse oscillometry (IOS) has been introduced as a complementary approach to conventional pulmonary function testing. Therefore, this study aimed to assess the efficacy of the diagnostic ability of IOS for diagnosing chronic obstructive pulmonary disease (COPD). This cross-sectional study was conducted at the Lung Health Center, Chiang Mai University, Thailand, between June 2019 and January 2020. IOS and spirometry were performed with all subjects suspected of having COPD. A Receiver Operating Characteristic (ROC) curve was plotted, the area under the ROC (AuROC) and 95%CI were compared among COPD and chronic smokers. One hundred and seventeen subjects suspected of having COPD with a mean age of 68.6 ± 8.6 years old were enrolled. Of these 103 (88.0%) were male. Thirty healthy subjects were also enrolled. IOS parameters including resistance at 5 Hz (R5), resonant frequency (Fres), area under reactance (AX), heterogeneity of resistance (R5-R20), and reactance at 5 Hz (X5) demonstrated excellent overall accuracy relative to the diagnosis of COPD with an AuROC ranging from 0.80 − 0.84. The AX ≥ 8.66 cmH₂O/L represented an AuROC = 0.79, with a sensitivity of 79.1% and a specificity of 78.0% for the diagnosis of COPD. IOS is a valuable tool for use in the diagnosis of COPD. It may be used in subjects who cannot carry out the spirometric procedure.

Keywords:

• COPD
• spirometry
• airway resistance
• smoking
• impulse oscillometry

Acknowledgments

The authors would like to thank all subjects who kindly participated in this study. The authors acknowledge the physicians and nurses of the Division of Pulmonary, Critical Care and Allergy, Department of Internal Medicine, Faculty of Medicine, Chiang Mai University for their contribution to this trial. Finally, we acknowledge the Faculty of Medicine Graduate Student Scholarship, Chiang Mai University for the supporting.

Disclosure statement

The authors have no conflicts of interest in connection with this work.

Author contributions

Conceptualization, W.C., S.N., C.L., and C.P.; Methodology, W.C., S.N., C.L.; and C.P. Software, W.C.; Validation, W.C., S.N., C.L., and C.P.; Formal Analysis, W.C., S.N.; Investigation, W.C., C.L., and C.P.; Resources, W.C., C.L., and C.P.; Data Curation, W.C. and C.P.; Writing – Original Draft Preparation, W.C.; Writing – Review & Editing, W.C., S.N., C.L., and C.P.; Visualization, W.C., S.N., C.L., and C.P.; Supervision, S.N., C.L., and C.P.; Project Administration, W.C. and C.P.; Funding Acquisition, W.C., S.N., and C.P. All authors have read and agreed to the published version of the manuscript.

Additional information

Funding

This study is funded by the Faculty of Medicine, Chiang Mai University Research Fund under grant No. 037/2563.